I don’t know who said it, maybe all of us said, ‘Oh my God. Look at that!’ and up came the Earth.

We had had no discussion on the ground, no briefing, no instructions on what to do. I jokingly said, ‘well it’s not on the flight plan,’ and the other two guys were yelling at me to give them cameras.

I had the only colour camera with a long lens. So I floated a black and white over to Borman. I can’t remember what Lovell got. There were all yelling for cameras, and we started snapping away.

Initially, both Borman and Anders claimed responsibility for the now-famous picture. An investigation of transcripts later revealed that Borman, who was the first to recognise the importance of the moment, took a black-and-white photo before Anders snapped the iconic colour photograph.

Fred Spier, a senior lecturer at the University of Amsterdam, notes in his article “The Elusive Apollo 8 Earthrise Photo” that Borman and Lovell each played a crucial part in prompting Anders, who had the only colour camera, to take the shot.

“Experienced astronaut Frank Borman was the first to the importance of the picture, while equally experienced astronaut James Lovell was quick to follow,” Spier writes.

“Space rookie William Anders, however, was in charge of taking the photos. In doing so, Anders had to follow a rather tight and well-defined photo plan, in which there was little or no room for unplanned snapshots.”

Spier continued: “Anders first offered some resistance and then quickly did what the other told him to do. Although it now seems beyond doubt that Anders actually snapped the famous picture, it also seems fair to say the picture came as a result of the combined efforts of all three astronauts.”